Quantifying microplastic pollution in South African mangrove forests: A comparative analysis of abundance, morphotype, polymer composition and toxicity.

Microplastic (MP) pollution is a global environmental threat and while the prevalence of MPs has been well characterised for many habitats, significant knowledge gaps exist for ecosystems like mangroves. This is particularly true for Africa, where baseline levels of MP pollution in many biodiverse ecosystems have yet to be established, hampering management interventions. This motivated the present study which aimed to profile MP pollution in four mangrove-dominated estuaries in the Eastern Cape, South Africa, through a comparative assessment of MP abundance, morphotypes, size, colour polymer composition and polymer toxicity, in relation to the types and intensity of anthropogenic and natural disturbances impacting these systems. The results showed that MP levels were highest in the sediment components of the estuaries studied, with MP abundances ranging from 2.78 MP items/kg to 13. 26 MP items per Kg in the sediment; and surface water MP abundances ranging from 0 MP items/L to 3 MP items/L. Overall, the results highlighted that systems exposed to higher levels of anthropogenic disturbances have higher levels and diversities of MPs. Whilst a wide diversity of MP morphotypes were detected, white microfibers dominated in the surface water and mangrove sediment (91 Also see: https://micro2024.sciencesconf.org/559775/document